Manufacture of telegraph and telephone conductors



Jan. 7, 1930. E. FISCHER 1,742,639

MANUFACTURE OF TELEGRnPH AND TELEPHONE CONDUCTORS Filed March 24, 1927 1/ 71 7JJJ7J H W am 5 m xm Patented Jan. 7, 1930 UNITED STATES PATENT OFFICE ERWERKE GESELLSCHAFT MIT IBESCHRANKTER HAFTUNG, OF KBERLIN-SIE'.I&IIEJIS-- STADT, GERMANY, A CORPORATION OF GERMANY MANUFACTURE OF TELEGRAPH AND TELEPHONE CONDUOTORS Application filed March 24, 1927, Serial No. 178,059, and in Germany March 16,1926.

' creased inductance, or uniformly loaded in the manner of the well known Krarup conductors. These conductors are for the purpose of 1ncreasmg the inductance provided with an envelope of magnetic material of high.

permeability which is wrapped around them. in the form of a tape or wire. In order that the magnetic material should have the required good magnetic properties itis necessary to anneal it at comparatively high temperatures. The annealing of the magnetic material takes place either after it has been wrapped around the conductor and together with the conductor or the ma netic material is annealed separately prior to eing wrapped around the conductor. In both methods the magnetic material is stretched during or after the annealing whereby it loses part of its good magnetic properties. When the magnetic material is annealed together with the conductor it is put under tension and stretched in consequenceof the expansion of the copper conductor. When, on the. other hand, the magnetic material is annealed prior to its application to the conductor it is stretched while being wound upon the conductor. Both methods have, full-thermore, the drawback in common that owing to the tensional strain developed when wrapping the magnetic material around the conductor it is necessary to use thicker strips or wire than would be required to attain the desired inductance. This causes in turn unnecessarily large eddy currents and hysteresis losses.

According to my invention-these drawbacks are eliminated by applying the previously annealed magnetic material unon a carrier or supporting member and then wrapping it together with this carrier around the conductor. In this way it is possible to wrap the magnetic material in a very thin layer around the conductor without it being subjected to detrimental strainssince during the wrapping around a corrugating of the magnetic material occurs which is preferably located upon the side of the'carrier facing the conductor and the tensional strains are taken up only by the carrier. The wires or tapes of magnetic material may be attached to the carrier in any known manner, for instance by; fixing them byan adhesive, wrapping or t e like. The magnetic material may be applied to the carrier or supporting member in the form of thin tapes or wires. Preferably the carrier is at the same time utilized as insulation for the conductor by constructing it of an insulating material, such as paper. In order to avoid an unnecessary thickening of the conductor at the overlapping points of the wrapping, the magnetic material is preferably applied to thecarrier in such a manner that it covers only a portion of it. In order to increase the safety against mechanical strains of the magnetic material still further, the magnetic material may prior to the application to the carrier be lightly corrugated by itself or after the apphcation to the carrier together with the carrier.

In the drawing affixed hereto some embodiments of my invention are illustrated by way of example.

The drawings represent in i Fig. 1, a conductor of a telephone cable, 1n

Fig. 2, a carrier with the magnetic material applied td it, both lightly corrugated, and in Fig. 3, a smooth carrier with corrugated magnetic material applied to it.

Referring to Fig. 1 of the drawing, 1 is the conductor of a telephone system The conductor is surrounded by magnetic material along its entire length. This magnetic material 3 is joined to a carrier 2 and together with it applied to the conductor in such a manner that it is located upon the side of the carrier facing the conductor. The carrier is only partially covered b the magnetic material in order that the iameter of the conductor may become uniform.

Referring to Fig.2, 2 is acarrier with the magnetic material 3, both of them being light- 1y corrugated are applied in this state to the 2 is smooth and only the magnetic material 3 is corrugated.

Various modifications and changes may be made without departing from the s irit and 5 the scope of the invention, and desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art.

I claim as my inventlon: 1. The method of manufacturing uniformly loaded telegraph and telephone conductors, which consists in combining the magnetic material with a carrier and applying the said magnetic material and the said carrier to-the conductor in such a manner that the magnetic material is located on the side of the carrier facing the conductor.

2. The method of manufacturing uni- I formly loaded telegraph and telephone conductors, which consists in combining the magnetic material with a carrier in such a manner, that the said ma netic material covers on the carrier side facmg the conductor only a portion of the carrier and applying the said magnetic material together with the said carrier to the conductor.

3. The method" of manufacturing uniformly loaded telegraph and teleghone conductors which consists in com ining the magnetic material with a carrier, lightly corrugating the carrier and the magnetic material and applyin the said magnetic material together wit the said carrier to the conductor, the ma etic material being located on the carrier side facing the conductor Q 4. As a new article of manufacture, a uniformly loaded telegraph or tele hone conductor having carrier-sup orte magnetic materiai surroundin sa1 conductor, the magnetic material being located on the side of the carrier facin the conductor.

5. Asa new artic e of manufacture, a uniformly loaded telegraph or telephone conductor in which the magnetic material sur- 46 rounding said conductor consists of a thin tape, attached to a carrier on the carrier side facing the conductor.

6. s a new article of manufacture, a uniformly loaded telegraph or telephone con- 50 ductor having carrier-sup crted corrugated ma netic material surroun ing the conductor an being located on the side of the carrier facing said conductor.

'In testimony whereof I afiix m signature.

as ERNST F SCHERL 

